An ill-defined mass (2.5 x 2.2 x 10.1 cm) is noted in the belly of the right adductor longus muscle. The lesion has slightly inhomogeneous high signal intensity on fat-saturated T2-weighted images, as compared with the normal musculature. After contrast injection, imaging reveals near homogenous enhancement of the mass. It is noteworthy that the muscle fibers within the lesion are preserved without disruption, helping to distinguish it from the other aggressive malignant diseases.